Examplify question bank 1/2

Question 1

One complication of subarachnoid haemorrhage is blockage of arachnoid granulations. What might the effect of this be?

A. Low intracranial pressure

B. No effect on intracranial pressure

C. Raised intracranial pressure

Answer 1

Raised intracranial pressure

Arachnoid granulations are involved with drainage of CSF. Hence CSF would accumulate and increase the pressure within the skull

Question 2

Which region on the image of midbrain is the cerebral peduncle?

A. A

B. B

C. C

Answer 2

C. C

Rationale: A is periaqueductal grey matter, B is substantia nigra

Question 3

A region of white matter is identified in the cord which contains both ascending and descending axons. What is the correct term for this?

A. Fasciculus

B. Funiculus

C. Tract

Answer 3

B. Funiculus

Rationale: A fasciculus is a subdivision of a tract. A tract contains axons travelling in a single direction only (either ascending or descending)

Question 4

Pure sensory loss in a single dermatome with no associated weakness suggests damage to which structure?

A. Dorsal root

B. Spinal cord

C. Ventral root

Answer 4

A. Dorsal root

Rationale: If the spinal cord ( part within the vertebral column) was damaged this would probably affect multiple dermatomes with associated weakness. If the ventral root was affected there would be weakness with no sensory loss. Dorsal roots contain sensory axons only

Question 5

Which subdivision of the CNS contains cell bodies and dendrites?

A. Choroid plexus

B. Grey matter

C. White matter

Answer 5

grey matter

Rationale: Choroid plexus makes CSF, white matter contains axons

Question 6

The thalamus, an important structure in the sensory system, is found in which division of the CNS?

A. Telencephalon

B. Mesencephalon

C. Diencephalon

Answer 6

C. Diencephalon

Rationale: The mesencephalon refers to the midbrain (meso=middle) and the telencephalon refers to the rostral most portions of the brain

Question 7

Which type of neurone brings information into the central nervous system?

A. Afferent neurones

B. Efferent neurones

C. Interneurones

Answer 7

A. Afferent neurones

Rationale: Efferent neurones carry impulses away from the CNS and interneurones connect afferents and efferents

Question 8

The hippocampus is found in which lobe of the brain?

A. Frontal lobe

B. Occipital lobe

C. Temporal lobe

Answer 8

Temporal lobe

Rationale: The hippocampus sits infero-medially in the temporal lobe

Question 9

Which cranial nerve emerges ventrally from the ponto-medullary junction?

A. Abducens nerve

B. Facial nerve
C. Trigeminal nerve

Answer 9

A. Abducens nerve

Rationale: The trigeminal nerve emerges from the lateral aspect of the pons. The facial nerve emerges laterally from the ponto-medullary junction

Question 10

The superior colliculus is part of which structure?

A. Medulla

B. Midbrain

C. Pons

Answer 10

Midbrain

Rationale: The colliculi sit on the dorsal aspect of the midbrain (and form Mickey mouse’s chin)

Question 11

A meningomyelocoele contains what?

A. CSF only

B .Spinal cord and CSF

C. Spinal cord but no CSF

Answer 11

B .Spinal cord and CSF

Rationale: Meningo- refers to meninges (and hence CSF) and –myelo refers to the cord. A Meningocoele has only CSF. Cord but no CSF is not possible

Question 12

The CNS shares an embryological origin with which other tissue?

A. The gut

B. The skin

C. Skeletal muscle

Answer 12

B. The skin

Rationale: CNS is derived from ectoderm, as is skin. Gut derives from endoderm and muscle from mesoderm

Question 13

Cerebrospinal fluid circulates in which space?

A. The extradural space

B. The subarachnoid space

C. The subdural space

Answer 13

B. The subarachnoid space

Rationale: The extradural space normally contains nothing (but can fill with blood in an extradural haemorrhage). The subdural space contains nothing normally, apart from bridging veins (but can fill with blood in a subdural haemorrhage)

Question 14

Considering the motor homunculus, which region of the body is represented most laterally in the primary motor cortex?

A. The face
B. The hand
C. The lower limb

Answer 14

A. The face

Rationale: The lower limbs are represented medially and the hand sits in an intermediate position

Question 15

Which region of cortex sits anterior to the central sulcus?

A. Premotor area
B. Primary motor cortex

C. Primary sensory cortex

Answer 15

B. Primary motor cortex

Rationale: The primary sensory cortex sits posterior to the central sulcus and the premotor area sits anterior to the primary motor cortex

Question 16

The cuneate fasciculus contains fibres from which body region?

A. C1 - T6

B. T7 - T12

C. L1-L5

Answer 16

C1-T6 (upper body)

Rationale: The gracile fasciculus contains information from the lower half of the body. The head is supplied by a separate system

Question 17

In the dorsal column, which population of first order fibres ascend most medially?

A. Cervical

B. Thoracic

C. Lumbar

Answer 17

lumbar

Question 18

A patient has a tumour compressing the left cerebral peduncle. What is the likely effect on the sensory system?

A. Loss of all modalities on the left side

B. Loss of all modalities on the right side

C. Nothing

Answer 18

Nothing

Rationale: For our purposes, the cerebral peduncle contains motor fibres only- ventral. Sensory fibres ascend directly to the thalamus via Mickey mouse’s ‘tears’

remember dorsal= sensory, ventral = motor

Question 19

A patient has a dorsal column lesion. What is likely to happen if they stand up and close their eyes?

A. Head will turn towards the side of the lesion

B. Nothing
C. They will lose their balance

Answer 19

They will lose their balance

Rationale: Equilibrium relies on having at least 2 out of three inputs to the brain: vision, proprioception and input from the vestibular system. Take two of these away (vision and proprioception in this case) and the patient will lose their balance.

Question 20

A patient has loss of all sensory modalities in the left T3 dermatome, loss of pain and temperature sensation from T4 downwards on the right side and loss of vibration and light touch from T4 downwards on the left side. Where is the lesion?

A. Left side of the T3 cord segment

B. Left side of the T4 cord segment

C. Right side of the T4 cord segment

Answer 20

A. Left side of the T3 cord segment

Rationale: This is Brown Sequard syndrome caused by cord hemisection. If the left T4 segment were destroyed you would see a similar pattern, but the T4 dermatome would lose all modalities. If the right half of the cord was affected then you would see right sided loss of dorsal column modalities and left sided loss of spinothalamic modalities (below the lesion)

Question 21

A patient who was involved in a road traffic accident describes how he felt no pain, despite the fact that his leg had been crushed. What is a feasible neurophysiological mechanism for this?

A. Destruction of all of the nerves supplying his lower limb

B. Increased activity of enkephalinergic neurones in the spinal cord

C. Inhibition of the somatosensory cortex

Answer 21

Increased activity of enkephalinergic neurones in the spinal cord

This is caused by activation of descending analgesic systems from the PAG and nucleus raphe magnus. Destruction of peripheral nerves often leads to increased sensations due to ectopic action potentials in first order neurones. Inhibition of the somatosensory cortex is not a major mechanism here.

Question 22

A patient has bilateral loss of temperature and pain sensation in the C6, C7 and C8 dermatomes. They have no other neurological signs. What is the most likely reason for this?

A. Bilateral thalamic tumours
B. Complete cord transection at C5
C. Syringomyelia affecting the C6-C8 cord segments

Answer 22

C. Syringomyelia affecting the C6-C8 cord segments

Rationale: Symmetrical signs are typically caused either by systemic or midline lesions. Bilateral thalamic tumours would be extremely unlikely and affect multiple modalities beyond the spinothalamic system. Complete cord transection would cause neurology in all systems below the lesion.

Question 23

A patient has loss of all sensory modalities confined to the medial surface of the upper limb including the medial surface of the hand. Where is the lesion most likely to be?

A. The contralateral thalamus
B. The ipsilateral C5 spinal cord segment

C. The ipsilateral C8 spinal nerve

Answer 23

The ipsilateral C8 spinal nerve

Rationale: I should have specified a side here (it is unilateral). Hence, this is a dermatomal pattern consistent with compression of a spinal nerve at C8. The C5 segment supplies a completely different region. A thalamic lesion would cause effects in a much bigger area, not confined to a dermatome.

Question 24

At what point do second order neurones of the spinothalamic system decussate?

A. At the level of entry of first order neurones

B. In the corona radiata
C. In the medulla

Answer 24

At the level of entry of first order neurones

Second order neurones in DC-ML system decussate in the medulla. There is no decussation in the corona radiata

Question 25

Vibration and two-point discrimination are carried in which pathways running through the cord?

A. Dorsal column
B. Dorsal spinocerebellar tract

C. Spinothalamic tract

Answer 25

Dorsal column

Question 26

In the dorsal-column medial lemniscus system first order neurones ascend the cord through which white matter region?

A. Dorsal funiculus

B. Lateral funiculus

C. Ventral funiculus

Answer 26

Dorsal funiculus

The lateral funiculus contains tracts such as the corticospinal and spinothalamic whereas the ventral funiculus contains the ventral corticospinal tract and a number of other small print pathways

Question 27

Cell bodies of primary sensory neurones can be found in which structures?

A. Dorsal root ganglia
B. Parasympathetic ganglia

C. Sympathetic ganglia

Answer 27

Dorsal root ganglia

Question 28

medulla mickey mouse

Answer 28

cerebral peduncles = ventral= motor

Question 30

The raphe nuclei produce which neurotransmitter?

A. 5-HT (serotonin)

B. Dopamine

C. Noradrenaline §

Answer 30

A. 5-HT (serotonin)

Rationale: Dopamine is produced by regions such as substantia nigra. Noradrenaline is produced by regions such as the locus coeruleus

Question 31

A tumour at the level of the interventricular foramen might lead to dilatation of which structures?

A. Fourth ventricle

B. Lateral ventricles

C. Third ventricle

Answer 31

B. Lateral ventricle

Rationale: The lateral ventricles drain to the interventricular foramen before entering the third ventricle.

Question 32

The third ventricle drains directly into which structure?

A. The central canal of the spinal cord

B. The cerebral aqueduct

C. The fourth ventricle

Answer 32

B. The cerebral aqueduct

Rationale: From the aqueduct CSF then goes to the fourth ventricle. The central canal of the cord emanates from the fourth ventricle and contains an insignificant amount of CSF

Question 33

Which part of the brainstem lies at the level of the tentorium cerebelli?

A. Medulla B. Midbrain C. Pons

Answer 33

B. midbrain

Rationale: The midbrain sits in the ‘tentorial notch’ and can be compressed if the uncus of the temporal lobe herniates into the posterior fossa

Question 34

So-called ‘bridging veins’ traverse which space?

A. The extradural space

B. The subarachnoid space

C. The subdural space

Answer 34

C. The subdural space

Rationale: The extradural space contain branches of the middle meningeal artery (rupture can lead to extradural haemorrhage). The subarachnoid space contains important arteries to the brain tissue itself (rupture can lead to subarachnoid haemorrhage)

Question 35

In the midbrain, which large white matter structures connect the cerebral hemispheres to the brainstem?

A. Cerebellar peduncles

B. Crus cerebri (cerebral peduncles)

C. Superior colliculi

Answer 35

B. Crus cerebri (cerebral peduncles)

Rationale: An alternative name for this is the cerebral peduncles. The cerebellar peduncles attach the cerebellum to the brainstem. The superior colliculi are features of the dorsal midbrain and deal with reflex actions to visual stimuli

Question 36

The falx cerebri is composed of which meningeal layer?

A. Arachnoid

B. Meningeal dura

C. Periosteal dura

Answer 36

B. Meningeal dura

Rationale: In the midline (sagittal plane) the meningeal dura separates from the periosteal layer and dips down between the hemispheres to form the falx. Periosteal dura is adhered directly to the inner table of the skull. Arachnoid sits deep to the meningeal dura

Question 37

An important source of dopamine for the motor system can be found in which structure?

A. The basal ganglia

B. The substantia nigra

C. The thalamus

Answer 37

B. The substantia nigra

Rationale: The substantia nigra resides in the midbrain (Mickey mouse’s eyebrows). The thalamus is an important sensory relay centre. The basal ganglia primarily contain inhibitory transmitters (but of course receive dopaminergic inputs from the SNc)

Question 38

Which of the following is an excitatory neurotransmitter?

A. GABA B. Glutamate C. Glycine

Answer 38

B. Glutamate

Rationale: Glutamate is the most common excitatory transmitter in the CNS. GABA is the most common inhibitory transmitter in the CNS. Glycine is inhibitory and has an important role in ‘paralysing’ lower motor neurones during REM sleep

Question 39

Which cell type can assume a macrophage-like appearance when activated?

A. Astrocytes B. Microglia C. Oligodendrocytes

Answer 39

Rationale: Microglia are an immune-type cell and oligodendrocytes myelinate CNS

Question 40

Which cell type is primarily responsible for maintenance of the bloodbrain barrier? A. Astrocytes B. Microglia C. Oligodendrocytes

Answer 40

A

Rationale: Microglia are an immune-type cell and oligodendrocytes myelinate CNS axons

Question 41

Amaurosis fugax (like curtains coming down) is a condition that is frequently caused by blockage of which artery?

A.Central retinal artery

B. Internal carotid artery

C. Thalamoperforator arteries

Answer 41

A.Central retinal artery

Rationale: This is transient blindness due to hypoxia in the retina. Occlusion of the internal carotid would cause widespread effects. Thalamoperforator arteries re branches of the posterior cerebral artery that supply the thalamus

Question 42

In addition to the cerebellum, which structure does the superior cerebellar artery also supply?

A. Midbrain

B. Pons

C. Thalamus.

Answer 42

midbrain

Rationale: The midbrain is supplied by the SCA on its way to the cerebellum. The pons is supplied by pontine branches from the basilar artery. The thalamus receives blood supply from the thalamoperforator branches of the PCA

Question 43

Thalamoperformator arteries are branches of which main artery?

A. Anterior cerebral

B. Middle cerebral

C. Posterior cerebral

Answer 43

C

Rationale: The middle cerebral arteries give off similar branches known as the lenticulostriate arteries, supplying the basal ganglia and internal capsule

Question 44

Which brain region is supplied by the middle cerebral artery?

A. Inferior surface of the temporal lobes

B. Lateral surface of the frontal and parietal lobes

C. Medial surface of the frontal and parietal lobes

Answer 44

B. Lateral surface of the frontal and parietal lobes

Rationale: The inferior temporal lobe is supplied by the posterior cerebral artery. The medial frontal and parietal lobe is supplied by the anterior cerebral artery.

Question 45

Internuclear ophthalmoplegia can be caused by damage to which pathway?

A. Medial forebrain bundle

B. Medial lemniscus

C. Medial longitudinal fasciculus

Answer 45

C. Medial longitudinal fasciculus

Rationale: The MLF helps to yoke eye movements together (and integrate input from the vestibular system). The medial forebrain bundle is a pathway relating to the hypothalamus (don’t worry about this). The medial lemniscus contains decussating second order sensory fibres in the DCML system

Question 46

Photoreceptor cells synapse with which retinal cell type predominantly?

A.Amacrine

B. Bipolar cells

C. Ganglion cells

Answer 46

Bipolar

Rationale: Amacrine cells are a type of ‘horizontal’ interneurone. Ganglion cells receive inputs from bipolar cells and project to the LGN. Bipolar cells can be thought of as the first order sensory neurones of the visual system

Question 47

Which of the following is a feature of the accommodation reflex?

A. Divergence of the eyes

B. Lens thickening

C. Pupillary dilatation

Answer 47

lens thickening

Rationale: The lens thicken to bend light rays more so that near objects stay in focus. The pupil normally constricts during accommodation (to help maintain focus). They eyes normally converge in accommodation

Question 48

Homonymous superior quadrantanopia is most commonly seen in lesions to which part of the visual pathway?

A. Lateral geniculate nucleus

B. Meyer’s loop

C. Visual cortex

Answer 48

B. Meyer’s loop

Rationale: Meyer’s loop (inferior optic radiation) contains fibres from the contralateral superior quarter of the field. This leads to a ‘pie in the sky’ defect. LGN lesions would cause a contralateral homonymous hemianopia. Visual cortex lesions would cause a contralateral homonymous hemianopia, possibly with macular sparing

Question 49

Destruction of the optic tract is rare. What would be the consequence of compression of the right optic tract?

A. Left homonymous hemianopia with macular sparing

B. Left homonymous hemianopia without macular sparing

C. Left superior homonymous quadrantanopia

Answer 49

B. Left homonymous hemianopia without macular sparing

Rationale: Macular sparing is a feature of (vascular) lesions of the occipital lobe. A right sided lesion would cause a left sided field defect. Superior quadrantanopias are caused by destruction of the inferior optic radiation (Meyer’s loop)

Question 50

A patient has a tumour arising from the right cavernous sinus and invading medially towards the optic chiasm. Which visual field defect might this result in?

A. Binasal hemianopia

B. Right homonymous hemianopia

C. Right nasal hemianopia

Answer 50

C. Right nasal hemianopia

Rationale: If the tumour erodes medially it will destroy fibres from the temporal retina of the right eye. The right temporal retina subserves the nasal field (of the right eye). Hence there will be a unilateral right nasal hemianopia. Binasal hemianopia is extremely rare and would be caused by a lesion eroding into both lateral aspects of the chiasm. A right homonymous hemianopia would be caused by a lesion from the left optic tract or posterior to this

Question 51

A patient suffers from sudden onset of complete monocular blindness. Which is the most likely site of a lesion?

A. Lateral geniculate nucleus

B. Optic chiasm

C. Optic nerve

Answer 51

C. Optic nerve

Rationale: Lesions at the chiasm or lateral geniculate would cause hemi field loss. Only a lesion in the optic nerve (or eye itself) could cause complete monocular blindness

Question 52

The lateral geniculate nucleus projects to which lobe?

A. Frontal lobe B. Occipital lobe C. Temporal lobe

Answer 52

B

Rationale: The LGN is part of the thalamus, relaying visual information from the optic tracts to the visual cortex. The medial geniculate nucleus is involved with auditory processing

Question 53

In which part of the retina are cones particularly common? A. Macula B. Optic disc C. Peripheral retina

Answer 53

A

Rationale: Cones are responsible for high acuity, colour vision and are positioned centrally at high density. The optic disc has no photoreceptors. The peripheral retina has predominantly rods.

Question 54

A patient complains of a transient loss of vision in one eye that resolved after four hours. Blockage of which vessel caused this?

A. Internal carotid artery B. Ophthalmic artery C. Posterior cerebral artery

Answer 54

B

Rationale: This is a typical story describing amaurosis fugax, which is transient blindness caused by blockage of the ophthalmic artery